Starting-switch for electric motors



(No Model.)

No. 453,367. PatentedJune 2,1891. zzyz 9a ftp/y 1 I I I UNITED STATES PATENT OFFICE. V

CLARK C. IIASKINS, OF CHICAGO, ILLINOIS.

STARTING-SWITCH FOR ELECTRIC MOTORS.

SPECIFICATION forming part of Letters Patent No. 453,367, dated June 2, 1891.

Application filed October 24, 1890. Serial No. 369,171. .(No model.)

To all whom, it may concern.-

Be it known that I, CLARK O. I-IAsKms, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement in Starting-Switches for Electric Motors, of which the following is a specification.

The starting-switch commonly employed with electric motors is a form of rheostat comprising a series of contact-plates disposed in a row describing an arc of a circle on a switch-board and connected in series by resistance-coils, the row containing also a dead or off contact at one end, while at the other end the terminal plate is connected directly with the outgoing line, the ingoing end thereof being connected with the switch-finger. The purpose of this arrangement is to enable the inertia of the motor in starting it to be gradually overcome by introducing the rheostat-resistance, and gradually reducing the resistance by slowly moving the switchfinger nearer and nearer the outgoing end of the switch, thereby cutting out the resistance as the inertia of the motor is overcome till it becomes safe to throw into it the full strength of the current.

Experience shows that the starting-switch attachment is sometimes carelessly used and sometimes misused, it having come under my notice that an operator is liable inadvertently to fail while attempting to cut off the current from the motor to turn the switch finger entirely back to the dead or off point, thereby leaving some current 011 which, while it is insufficient to work the motor, is sufficient to generate enough heat to entail the danger of fire. It has also come under my notice that an operator, in warm weather, under the mistaken intention of thereby saving current will purposely leave the switch partially turned on, thereby running the m0- tor with the current weakened by the interposed resistance. Both these instances have in my experience caused fire and resultant damage. My object is to provide means whereby such displacement of the switch-fin- .ger shall be effectually prevented.

In the accompanying drawings, Figure 1 is a plan View of astarting-switch provided with my improvement; Fig. 2, a section taken on the line 2 2 of Fig. 1 and viewed in the direction of the arrows; and Fig. 3, a broken View of the device regarded in the direction of the arrow from the line 3 in Fig. 1.

A is the switch-board provided with a row of contact-platesr, q, and 19, disposed in the arc of a circle, the first-named being an isolated piece, the intermediate ones (1 (of which three are shown) being connected one with the other and with the terminal contact p by resistanee-coils 0, and the last-named 1) being connected with the line by the wire it.

B is the switch-finger, pivoted on the board A at the center of the circle of which the contacts form an arc, and which is connected by the wire m with the return-circuit.

As thus far described, the construction need present no features of novelty, that shown being an old and well-known form of switch.

For my purpose the finger B yields in a direction perpendicular to the surface of the board A, provided with the contacts, and to render it so yielding I form it in sectionsl and Z, hinged together at 00, the outermost section being controlled by a spring 7.;, extending against it from the section 1, to be held at the forward end of the finger yieldingly against the contact-plate r or p, with reference to which it is adjusted.

C is a bridge, of any suitable material, extending lengthwise over the series of contact-plates q. I support the bridge at the end nearest the contact 0'' pivotally on a shaft tin a bearing hbeyond the row of contacts, where it is out of the path of the finger, and cause the opposite end of the bridge, preferably bent or curved, as shown, for the purpose, to extend into the path of the finger at or near the last of the series of contacts q, in which position it is normally held yieldingly and which it tends, by the action of aspring g on the shaft '1, to resume when raised on its pivot.

The finger B should be resilient to tend to return autom atically'from any point to which it is moved from the plate 0. Hence I provide at its pivoted enda spring f, which is set by turning the finger toward the contact 23 and the resilience of which thus will return it to the off contact 0' in case it should not be moved past the free end of the bridge. At the contact 19 a catch (2 serves to engage the finger when moved to the said contact and prevents its return until released from the catch.

From the foregoing description it will be seen that the finger B may be turned without obstruction toward the end contact p, in reaching which from the adjacent contact it must raise the bridge at its free end to pass it, which, however, immediately thereafter resumes its normal position, wherein it precludes the return of the finger upon the contacts, necessitating that it pass along the upper side of the bridge, to which it is guided in the return, thereby precluding the possibility of its being misplaced, as in the manner stated.

\Vhile the construction of my improvement is the best known to me for my purpose, it may be variously changed without thereby producing a departure from my invention.

\Vhat I claim as new, and desire to secure by Letters Patent, is-

1, In combination with a rheostat-switch, a pivotal switch-finger B, controlled by a spring to return automatically to the off point from any contact to which it is turned therefrom, a bridge yieldingly supported to extend over the contacts and normally obstructing the return upon the contacts of the said finger, and a catch for retaining the finger in opposition to its said spring at the terminal contact, substantially as and for the purpose set forth.

2. In combination with a rheostat-switch having the contacts q and p, a switch-finger B, formed with hinged sections Z and Z, controlled by a spring 7;, and a spring-controlled bridge C, pivotally supported from one end to extend over the contacts q into the path of the finger near the contact p,substantially as and for the purpose set forth.

3. In combination with a rheostat-switch having the contacts qand p, aflexible switchfinger B, controlled by a spring f to return it automatically to the off point from any contact to which it is turned therefrom, a bridge 0, pivotally supported at one end to extend over the contacts q, and projecting at its free end into the path of the switch-finger between the contact 1) and the adjacent contact q, and a catch e for retaining the finger in opposition to the springf at the terminal contact, substantially as and for the purpose set forth.

4:. In combination with a rheostat-switch having the contacts (1 and p, a switch-finger B, formed with hinged sections 1 and Z, controlled by a spring in, a spring f, set by turning the switch 011 and operating by its resilience to return the finger,a spring-controlled bridge 0, pivotally supported from one end in a bearing h outside the path of the finger to extend over the contacts q into the path of the finger near the contact 17, and a catch c for retaining the finger in opposition to the spring f at the contact 13, substantially as and for the purpose set forth.

CLARK (J. IIASKINS. In presence of J. W. DYRENFORTH, M J. Fnos'r. 

